Missing pensioner Alexander Stuart Nicol could be anywhere in the country, police said.

It has been four days since the 73-year-old was last seen leaving his home in Eslington Terrace, Jesmond, Newcastle.

Now the search for him has gone nationwide.

Police are continuing to build up a profile of Mr Nicol by speaking to his family, friends and neighbours.

Supt Paul Orchard, of Northumbria Police, said officers are very concerned about his disappearance which is out of character.

He also described Mr Nicol, who is a retired librarian, as a quiet person who regularly visits Tynemouth, Brunswick Methodist Church and Newcastle City Library.

Concerns grew when he did not return for a Burns Night celebration he had planned for friends and neighbours at 7pm on Friday night.

A team of officers are following up several lines of inquiry in an urgent attempt to find Mr Nicol.

He left his home on Friday morning and was caught on CCTV arriving at Jesmond Metro Station at around 9.25am, before boarding a train heading towards Newcastle Airport at 9.33am.

He got off the Metro at Regent Centre at 9.41am and turned right from the station, walking a loop around the main bus area, possibly looking at bus timetables. He then walked towards Gosforth Library before spending around 10 minutes inside the building and leaving.

Mr Nicol was last seen heading back in the direction of the bus stops at Regent Centre from the library.

He was wearing a light beige overcoat, grey checked hat, dark trousers and shoes, black gloves and a checked scarf. He is not believed to be suffering from any medical conditions or ill health but there are growing fears for his whereabouts. Police have put posters up around the area, and urge anyone who has any information to come forward. Supt Orchard said: “We’ve been carrying out extensive inquiries to locate him. The last known sighting was of him heading in the direction of bus stops in Gosforth and it’s possible he may have left the area. He’s not believed to be suffering from any medical conditions or ill health but we’re concerned he may have boarded a bus and may have become ill or confused.

Anyone with any information should contact Northumbria Police on 101, extension 69191.